Ultrasound sequencing system and method

ABSTRACT

A system comprises a catheter configured for delivery to a body cavity defined by surrounding tissue; a plurality of ultrasound transducers coupled to a distal end of the catheter; and an electronics module configured to selectively turn on/off each ultrasound transducer according to a predetermined activation sequence and to process signals received from each ultrasound transducer to produce at least a 2D display of the surrounding tissue. A user can selectively calculate and display various aspects of cardiac activity. The user can display Dipole Density (DDM), Charge Density (CDM), or Voltage (V-V). The shape and location of the chamber (surface), and the potentials recorded at electrodes can be displayed. The system can also change back and forth between the different display modes, and with post processing tools, can change how various types of information is displayed. Methods are also provided.

RELATED APPLICATIONS

The present application claims priority under 35 USC 119(e) to U.S.Provisional Patent Application Ser. No. 62/160,529, entitled “UltrasoundSequencing System and Method”, filed May 12, 2015, which is incorporatedherein by reference in its entirety.

The present application, while not claiming priority to, may be relatedto U.S. patent application Ser. No. 14/865,435, entitled “Method andDevice for Determining and Presenting Surface Charge and DipoleDensities on Cardiac Walls”, filed Sep. 25, 2015, which is acontinuation of U.S. Pat. No. 9,167,982 (hereinafter the '982 patent),entitled “Method and Device for Determining and Presenting SurfaceCharge and Dipole Densities on Cardiac Walls”, issued Oct. 27, 2015,which is a continuation of, which is a continuation of U.S. Pat. No.8,918,158 (hereinafter the '158 patent), entitled “Method and Device forDetermining and Presenting Surface Charge and Dipole Densities onCardiac Walls”, issued Dec. 23, 2014, which is a continuation of U.S.Pat. No. 8,700,119 (hereinafter the '119 patent), entitled “Method andDevice for Determining and Presenting Surface Charge and DipoleDensities on Cardiac Walls”, issued Apr. 15, 2014, which is acontinuation of U.S. Pat. No. 8,417,313 (hereinafter the '313 patent),entitled “Method and Device for Determining and Presenting SurfaceCharge and Dipole Densities on Cardiac Walls”, issued Apr. 9, 2013,which was a 35 USC 371 national stage filing of Patent CooperationTreaty Application No. CH2007/000380, entitled “Method and Device forDetermining and Presenting Surface Charge and Dipole Densities onCardiac Walls”, filed Aug. 3, 2007, published as WO2008/014629, whichclaimed priority to Swiss Patent Application No. 1251/06 filed Aug. 3,2006, each of which is hereby incorporated by reference.

The present application, while not claiming priority to, may be relatedto U.S. patent application Ser. No. 14/886,449, entitled “Device andMethod for the Geometric Determination of Electrical Dipole Densities onthe Cardiac Wall”, filed Oct. 19, 2015, which is a continuation of U.S.Pat. No. 9,192,318, entitled “Device and Method for the GeometricDetermination of Electrical Dipole Densities on the Cardiac Wall”,issued Nov. 24, 2015, which is a continuation of U.S. Pat. No.8,512,255, entitled “Device and Method for the Geometric Determinationof Electrical Dipole Densities on the Cardiac Wall”, issued Aug. 20,2013, published as US201010298690 (hereinafter the '690 publication),which was a 35 USC 371 national stage application of Patent CooperationTreaty Application No. PCT/IB09/00071 filed Jan. 16, 2009, entitled “ADevice and Method for the Geometric Determination of Electrical DipoleDensities on the Cardiac Wall”, published as WO2009/090547, whichclaimed priority to Swiss Patent Application 00068/08 filed Jan. 17,2008, each of which is hereby incorporated by reference.

The present application, while not claiming priority to, may be relatedto U.S. patent application Ser. No. 14/003,671, entitled “Device andMethod for the Geometric Determination of Electrical Dipole Densities onthe Cardiac Wall”, filed Sep. 6, 2013, which is a 35 USC 371 nationalstage filing of Patent Cooperation Treaty Application No.PCDUS2012/028593, entitled “Device and Method for the GeometricDetermination of Electrical Dipole Densities on the Cardiac Wall”,published as WO2012/122517 (hereinafter the '517 publication), whichclaimed priority to U.S. Patent Provisional Application Ser. No.61/451,357, each of which is hereby incorporated by reference.

The present application, while not claiming priority to, may be relatedto U.S. Design application Ser. No. 29/475,273, entitled “CatheterSystem and Methods of Medical Uses of Same, Including Diagnostic andTreatment Uses for the Heart”, filed Dec. 2, 2013, which is a 35 USC 371national stage filing of Patent Cooperation Treaty Application No.PCT/US2013/057579, entitled “Catheter System and Methods of Medical Usesof Same, Including Diagnostic and Treatment Uses for the Heart”, filedAug. 30, 2013, which claims priority to U.S. Patent ProvisionalApplication Ser. No. 61/695,535, entitled “System and Method forDiagnosing and Treating Heart Tissue”, filed Aug. 31, 2012, which ishereby incorporated by reference.

The present application, while not claiming priority to, may be relatedto U.S. patent application Ser. No. 14/762,944, entitled “ExpandableCatheter Assembly with Flexible Printed Circuit Board (PCB) ElectricalPathways”, filed Jul. 23, 2015, which is a 35 USC 371 national stagefiling of Patent Cooperation Treaty Application No. PCT/US2014/15261,entitled “Expandable Catheter Assembly with Flexible Printed CircuitBoard (PCB) Electrical Pathways”, filed Feb. 7, 2014, published asWO2014/124231, which claims priority to U.S. Patent ProvisionalApplication Ser. No. 61/762,363, entitled “Expandable Catheter Assemblywith Flexible Printed Circuit Board (PCB) Electrical Pathways”, filedFeb. 8, 2013, which is hereby incorporated by reference.

The present application, while not claiming priority to, may be relatedto Patent Cooperation Treaty Application No. PCT/US2015/11312, entitled“Gas-Elimination Patient Access Device”, filed Jan. 14, 2015, whichclaims priority to U.S. Patent Provisional Application Ser. No.61/928,704, entitled “Gas-Elimination Patient Access Device”, filed Jan.17, 2014, which is hereby incorporated by reference.

The present application, while not claiming priority to, may be relatedto Patent Cooperation Treaty Application No. PCT/US2015/22187, entitled“Cardiac Analysis User Interface System and Method”, filed Mar. 24,2015, which claims priority to U.S. Patent Provisional Application Ser.No. 61/970,027, entitled “Cardiac Analysis User Interface System andMethod”, filed Mar. 28, 2014, which is hereby incorporated by reference.

The present application, while not claiming priority to, may be relatedto U.S. application Ser. No. 14/916,056, entitled “Devices and Methodsfor Determination of Electrical Dipole Densities on a Cardiac Surface”,filed Mar. 2, 2016, which is a 35 USC 371 national stage filing ofPatent Cooperation Treaty Application No. PCT/US2014/54942, entitled“Devices and Methods for Determination of Electrical Dipole Densities ona Cardiac Surface”, filed Sep. 10, 2014, published as WO2015/038607,which claims priority to U.S. Patent Provisional Application Ser. No.61/877,617, entitled “Devices and Methods for Determination ofElectrical Dipole Densities on a Cardiac Surface”, filed Sep. 13, 2013,which is hereby incorporated by reference.

FIELD

The present invention is generally related to systems and methods thatmay be useful for the diagnosis and/or treatment of cardiac arrhythmiasor other cardiac diseases or disorders, such as systems, devices, andmethods that may be useful in mapping cardiac activity.

BACKGROUND

For localizing the origin(s) of cardiac arrhythmias it is commonpractice to measure the electric potentials located on the inner surfaceof the heart by electrophysiological means within the patient's heart.One method is to insert electrode catheters into the heart to recordcardiac potentials during normal heart rhythm or cardiac arrhythmia. Ifthe arrhythmia has a regular activation sequence, the timing of theelectric activation measured in voltage at the site of the electrode canbe accumulated when moving the electrode around during the arrhythmia,to create a three-dimensional map of the electric activation. By doingthis, information on the location of the source of arrhythmia(s) andmechanisms, i.e., re-entrant circuits, can be diagnosed to initiate orguide treatment (radiofrequency ablation). The information can also beused to guide the treatment of cardiac resynchronization, in whichimplantable pacing electrodes are placed in specific locations withinthe heart wall or chambers to re-establish a normal level of coordinatedactivation of the heart.

A method using external sensors measures the electrical activity of theheart from the body surface using electrocardiographic techniques thatinclude, for example, electrocardiograms (ECG) and vectorcardiography(VCG). These external sensor techniques can be limited in their abilityto provide information and/or data on regional electrocardiac activity.These methods can also fail to localize bioelectric events in the heart.

A method using external sensors for the localization of cardiacarrhythmias utilizes body surface mapping. In this technique, multipleelectrodes are attached to the entire surface of the thorax and theinformation of the cardiac electrograms (surface ECG) is measured involtages that are accumulated into maps of cardiac activation. Thismeasurement can be problematic because the electrical activity is timedependent and spatially distributed throughout the myocardium and alsofails to localize bioelectric events in the heart. Complex mathematicalmethods are required to determine the electrical activation upon theouter surface of a heart model (i.e. epicardium), for instance, oneobtained from CT or MRI imaging giving information on cardiac size andorientation within the thoracic cavity.

Alternatively, recordings of potentials at locations on the torso, forexample, can provide body surface potential maps (BSPMs) over the torsosurface. Although the BSPMs can indicate regional cardiac electricalactivity in a manner that can be different from conventional ECGtechniques, these BSPM techniques generally provide a comparatively lowresolution, smoothed projection of cardiac electrical activity that doesnot facilitate visual detection or identification of cardiac eventlocations (e.g., sites of initiation of cardiac arrhythmias) and detailsof regional activity (e.g., number and location of arrythmogenic foci inthe heart).

Since the localization of cardiac arrhythmias by the use of potentialsis imprecise, the successful treatment of cardiac arrhythmias has beendifficult and has demonstrated limited success and reliability. Thereis, therefore, a need for improved methods of localizing, diagnosing andtreating cardiac arrhythmias.

SUMMARY

In accordance with one aspect of the inventive concept, provided is abody cavity imaging system, comprising: a catheter configured fordelivery to a body cavity defined by surrounding tissue; a plurality ofultrasound transducers coupled to a distal end of the catheter; anelectronics module configured to selectively turn on/off each ultrasoundtransducer according to a predetermined activation sequence and toprocess signals received from each ultrasound transducer to produce atleast a 2D display of the surrounding tissue.

In various embodiments, the imaging system can be part of anelectrophysiology system.

In various embodiments, the cavity can be a heart chamber and thesurrounding tissue can be one or more walls of the heart chamber.

In various embodiments, the display can be a 3D display of thesurrounding tissue.

In various embodiments, the 3D display of the surrounding tissue can bepresented on a user interface system having a display screen and usercontrol mechanism enabling graphical manipulation of the 3D display ofthe surrounding tissue.

In various embodiments, the graphical manipulation can include one ormore of zoom in/out, rotate, select portions or subsections of thesurrounding tissue.

In various embodiments, the plurality of ultrasound transducers can becoupled to a 3D array.

In various embodiments, the 3D array can be a basket array, spiralarray, a balloon, radially deployable arms, and/or other expandable andcompactible structures.

In various embodiments, the ultrasound transducers can be disposed on aplurality of splines of the 3D array.

In various embodiments, the 3D array can include at least three splines.

In various embodiments, at least two ultrasound transducers can bedisposed on each spline.

In various embodiments, the system can further comprise a plurality ofbiopotential electrodes coupled to a distal end of the catheter.

In various embodiments, the biopotential electrodes can also be disposedon a plurality of splines of the 3D array.

In various embodiments, at least some of the biopotential electrodes andat least some of the ultrasound transducers can be disposed on the samesplines.

In various embodiments, a biopotential electrode and an ultrasoundtransducer are disposed together to form an electrode/transducer pair,and the system includes a plurality of electrode/transducer pairs.

In various embodiments, one or more splines can comprise at least oneelectrode/transducer pair.

In various embodiments, one or more splines can comprise a plurality ofelectrode/transducer pairs.

In various embodiments, a plurality of splines can comprise at least oneelectrode/transducer pair.

In various embodiments, a plurality of splines can comprise a pluralityof electrode/transducer pairs.

In various embodiments, a plurality of splines can comprise at leastthree electrode/transducer pairs.

In various embodiments, each spline can comprise a flexible PCB, andeach electrode/transducer pair is electrically coupled to the flexiblePCB.

In various embodiments, each electrode/transducer pair can share acommon communication path on the flexible PCB.

In various embodiments, all electrode/transducer pairs on a spline canshare a common communication path on the flexible PCB.

In various embodiments, the common communication path can be a commonground.

In various embodiments, the system can be further configured tocorrelate cardiac or other electrical activity to one or more imagesgenerated using imaging device.

In various embodiments, the imaging device can comprise an imagingdevice selected from the group consisting of: a fluoroscope; an MRI; aCT Scanner; an ultrasound imaging device; and combinations of two ormore of these.

In various embodiments, the activation sequence can be a pattern ofturning on/off the plurality of ultrasound transducers that avoids thesequential activation of two neighboring ultrasound transducers.

In various embodiments, the activation sequence can avoid the sequentialactivation of two transducers within two or three neighboring spaces ofeach other.

In various embodiments, the neighboring spaces can be considered spaceson a single spline; across splines, such as transducer 1 of spline 1 andtransducer 1 of spline 2; and/or diagonally across splines, such astransducer 1 of spline 1 and transducer 2 of spline 2.

In various embodiments, the activation sequence pattern can be a patternthat avoids sequential activation of two transducers from a singlespline.

In accordance with another aspect of the inventive concept, provided isa method of performing a diagnostic assessment, comprising: providing acardiac diagnostic system, including a plurality of ultrasoundtransducers and a plurality of electrodes coupled to the end of adiagnostic catheter; inserting the diagnostic catheter into a heartchamber of a patient; placing the cardiac diagnostic system in adiagnostic mode; performing a biopotential measurement process;performing a localization process; performing an ultrasound measurementprocess; and interleaving a localization process and the ultrasoundprocess.

In various embodiments, frequencies of the ultrasound transducers do notinterfere with biopotential signals and biopotential signals do notinterfere with localization signals.

In various embodiments, the biopotential measurement process can beperformed continuously.

In various embodiments, the biopotential measurement process can beinterleaved with the localization process and the ultrasound measurementprocess.

In various embodiments, the method can comprise performing thelocalization process longer than, or multiple times for, a singleultrasound measurement process.

In various embodiments, the method can comprise performing theultrasound measurement process longer than, or multiple times for, asingle localization process.

In various embodiments, the biopotential measurement process can includemeasuring and analyzing biopotentials from the electrodes.

In various embodiments, the biopotential measurement process can includedetermining dipole densities and/or surface charge densities from thebiopotential data.

In accordance with another aspect of the inventive concepts, provided isa method of performing a localization process, comprising: providing acardiac diagnostic system, including a plurality of biopotentialelectrodes and, optionally, a plurality of ultrasound transducerscoupled to a distal end of a catheter; inserting the diagnostic catheterinto a heart chamber of a patient; placing one or more pairs of surfaceelectrodes on the patient and defining an individual axis for each pairof electrodes; generating one or more localization signals andtransmitting same to the patient through the one or more pairs ofsurface electrodes; recording data collected from the one or more pairsof surface electrodes; filtering the recorded data to isolate signalscorrelating to the generated localization signals of each pair ofsurface electrodes; analyzing the filtered data to determine a locationof each biopotential electrode in a coordinate system relative to thepatient, the coordinate system defined by the one or more pairs ofsurface electrodes.

In various embodiments, there can be at least two pairs of electrodes,and one individual axis can be determined for each pair of surfaceelectrodes.

In various embodiments, there can be at least three pairs of electrodes,and one individual axis is determined for each pair of surfaceelectrodes.

In various embodiments, the three axes can define a three axislocalization system.

In various embodiments, the coordinate system can be a 3D coordinatesystem.

In various embodiments, an origin of the coordinate system can belogically located within the heart of the patient.

In various embodiments, the method can comprise: placing surfaceelectrodes from a first pair on the chest and back of the patient,defining a first axis; and/or placing surface electrodes from a secondpair laterally on the sides of the patient, defining a second axis;and/or placing surface electrodes from a third pair on the neck orshoulder and thigh of the patient, defining a third axis.

In various embodiments, the method can comprise: placing surfaceelectrodes from a first pair of electrodes laterally on the sides of thepatient, defining a first axis; and/or placing surface electrodes from asecond pair of electrodes on the upper chest and lower back of thepatient, defining a second axis; and/or placing surface electrodes froma third pair of electrodes on the upper back and lower chest of thepatient, defining a third axis.

In various embodiments, each pair of surface electrodes can beindividually driven with a signal having a different frequency.

In various embodiments, localization signals can be generated at afrequency in a range of about 1-100 kHz.

In various embodiments, the signals from each pair of surface electrodescan be individually recorded.

In various embodiments, the signals from each pair of surface electrodescan be individually filtered.

In various embodiments, the localization process can be interleaved withan ultrasound measurement process of the cardiac diagnostic system.

In various embodiments, the localization process can be interleaved witha biopotential measurement process of the cardiac diagnostic system.

In accordance with aspects of the inventive concept, provided is amethod of performing an ultrasound measurement process, comprising:providing a cardiac diagnostic system, including a plurality ofultrasound transducers and, optionally, a plurality of biopotentialelectrodes coupled to a distal end of a catheter; inserting thediagnostic catheter into a heart chamber; activating (or ringing) anultrasound transducer to generate an ultrasound transducer signal;ringing down the ultrasound transducer; sensing and recording areflection of the ultrasound transducer signal by a source; determininga distance from the transducer to the source based on the receivedreflection; repeating the above steps until all ultrasound transducershave been activated; and repeating the above steps for all ultrasoundtransducers until the ultrasound measurement process is complete orended.

In various embodiments, the biopotential electrodes and ultrasoundtransducers can be paired to form electrode/transducer pairs.

In various embodiments, the electrode/transducer pairs can be disposedon a plurality of splines of a 3D array.

In various embodiments, activating an ultrasound transducer can includeclosing one or more switches, thereby electrically connecting thetransducer to a signal generator.

In various embodiments, the one or more switches can comprise anopto-coupler.

In various embodiments, the opto-coupler can have an activation time ina range of about 0.01 μs, or 500 μs.

In various embodiments, activating the transducer can include generatinga pulsed drive signal configured to ring, vibrate, and/or otherwisecause the transducer to generate an ultrasonic pulse.

In various embodiments, the drive signal can comprise a signal with afrequency in a range of about 1 MHz and 25 MHz, such as 10 MHz.

In various embodiments, the drive signal frequency can be about 10 MHz.

In various embodiments, the drive signal can e comprise a signal with apulse width in a range of about 0.1 μs and 10 μs.

In various embodiments, the drive signal pulse width can be about 2 μs.

In various embodiments, the ring down can have a duration of betweenabout 0.05 μs and 1 μs for dissipation of vibration of the ultrasoundtransducer.

In various embodiments, the ring down can have a duration of about 0.1μs.

In various embodiments, sensing the reflection can be performed for aduration in a range of about 1 μs and 200 μs.

In various embodiments, the sensing duration can be about 100 μs.

In various embodiments, the source can be an inner wall of a cardiacchamber.

In various embodiments, the activation of the transducer can causedeactivation of a paired biopotential electrode.

In various embodiments, the method can further comprise non-sequentiallyactivating electrode/transducer pairs, thereby not broadening atemporary “blind spot” of a neighboring biopotential electrode caused bythe activation of the ultrasound transducer.

In various embodiments, the patient can be a living being.

In various embodiments, the patient can be a simulated being or heart.

In accordance with aspects of the inventive concept, provided is a bodycavity imaging system as shown and/or described.

In accordance with aspects of the inventive concept, provided is acardiac diagnostic system as shown and/or described.

In accordance with aspects of the inventive concept, provided is acardiac diagnostic process as shown and/or described.

In accordance with aspects of the inventive concept, provided is alocalization process as shown and/or described.

In accordance with aspects of the inventive concept, provided is abiopotential measurement process as shown and/or described.

In accordance with aspects of the inventive concept, provided is anultrasound imaging method as shown and/or described.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a schematic view of an exemplary embodiment of acardiac analysis system comprising a catheter with an assembly includingmultiple electrical components that can be deployed within a body, inaccordance with aspects of the present inventive concepts.

FIG. 2 provides a flowchart of an embodiment of a method of performing adiagnostic assessment, in accordance with aspects of the presentinventive concepts.

FIG. 3 provides a flowchart of an embodiment of a method of performing alocalization process, in accordance with aspects of the presentinventive concepts.

FIG. 4 provides a flowchart of an embodiment of a method of performingan ultrasound measurement process, in accordance with aspects of thepresent inventive concepts.

FIG. 5 provides a perspective view of an embodiment of a diagnosticcatheter, in accordance with aspects of the present inventive concepts.

FIG. 5A is a perspective view of the catheter of FIG. 5 in an alteredshape, in accordance with aspects of the present inventive concepts.

FIG. 6 provides a representation of an embodiment of an activationsequence of an array of ultrasound transducers disposed on six splines,in accordance with aspects of the present inventive concepts.

FIG. 7 provides an embodiment of a block diagram of a user interfacesystem that can be used with a diagnostic catheter as described herein,for example, in accordance with the present inventive concepts.

FIGS. 8A-8C provide different views relating to the output of the userinterface system, in accordance with aspects of the present inventiveconcepts.

FIG. 9 provides a functional block diagram of an embodiment of a cardiacinformation processing system, in accordance with the present inventiveconcepts.

DETAILED DESCRIPTION

Various exemplary embodiments will be described more fully hereinafterwith reference to the accompanying drawings, in which some exemplaryembodiments are shown. The present inventive concepts can, however, beembodied in many different forms and should not be construed as limitedto the exemplary embodiments set forth herein.

It will be understood that, although the terms first, second, etc. areused herein to describe various elements, these elements should not belimited by these terms. These terms are used to distinguish one elementfrom another, but not to imply a required sequence of elements. Forexample, a first element can be termed a second element, and, similarly,a second element can be termed a first element, without departing fromthe scope of the present invention. As used herein, the term “and/or”includes any and all combinations of one or more of the associatedlisted items. And a “combination” of associated listed items need notinclude all of the items listed, but can include all of the itemslisted.

It will be understood that when an element is referred to as being “on”or “attached”, “connected” or “coupled” to another element, it can bedirectly on or connected or coupled to the other element or interveningelements can be present. In contrast, when an element is referred to asbeing “directly on” or “directly connected” or “directly coupled” toanother element, there are no intervening elements present. Other wordsused to describe the relationship between elements should be interpretedin a like fashion (e.g., “between” versus “directly between,” “adjacent”versus “directly adjacent,” etc.).

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting of the invention. Asused herein, the singular forms “a,” “an” and “the” are intended toinclude the plural forms as well, unless the context clearly indicatesotherwise. It will be further understood that the terms “comprises,”“comprising,” “includes” and/or “including,” when used herein, specifythe presence of stated features, steps, operations, elements, and/orcomponents, but do not preclude the presence or addition of one or moreother features, steps, operations, elements, components, and/or groupsthereof.

Spatially relative terms, such as “beneath,” “below,” “lower,” “above,”“upper” and the like can be used to describe an element and/or feature'srelationship to another element(s) and/or feature(s) as, for example,illustrated in the figures. It will be understood that the spatiallyrelative terms are intended to encompass different orientations of thedevice in use and/or operation in addition to the orientation depictedin the figures. For example, if the device in the figures is turnedover, elements described as “below” and/or “beneath” other elements orfeatures would then be oriented “above” the other elements or features.The device can be otherwise oriented (e.g., rotated 90 degrees or atother orientations) and the spatially relative descriptors used hereininterpreted accordingly.

Various exemplary embodiments are described herein with referenceillustrations of idealized or representative structures and intermediatestructures. As such, variations from the shapes of the illustrations asa result, for example, of manufacturing techniques and/or tolerances,are to be expected. Thus, exemplary embodiments should not be construedas limited to the particular shapes of regions illustrated herein butare to include deviations in shapes that result, for example, frommanufacturing.

To the extent that functional features, operations, and/or steps aredescribed herein, or otherwise understood to be included within variousembodiments of the present inventive concepts, such functional features,operations, and/or steps can be embodied in functional blocks, units,modules, operations and/or methods. And to the extent that suchfunctional blocks, units, modules, operations and/or methods includecomputer program code, such computer program code can be stored in acomputer readable medium, e.g., such as non-transitory memory and media,that is executable by at least one computer processor.

Referring now to FIG. 1, a schematic view of an embodiment of a cardiacanalysis system comprising a catheter with an assembly includingmultiple electrical components that can be deployed within a body isillustrated, consistent with the present inventive concepts. System 10includes diagnostic catheter 100 and electronics module 200. In someembodiments, system 10 can further include an introducer 50 and/orimaging device 80. Introducer 50 comprises handle 51 and elongate shaft55. Shaft 55 comprises at least one lumen, such as a lumen configured toslidingly receive diagnostic catheter 100 within shaft 55. In someembodiments introducer 50 comprises a transseptal access sheath or otherdevice configured to provide access to a body space or cavity, such as aheart chamber, for example. Handle 51 can include a knob, lever, switchor other control, generally referred to herein as control 52. Control 52can be configured to steer or otherwise deflect the distal end ofintroducer 50. Imaging device 80 can comprise an imaging device selectedfrom the group consisting of: a fluoroscope; an MRI; a CT Scanner; anultrasound imaging device; and combinations of two or more of these.However, other imaging devices could be used in various embodiments.

Diagnostic catheter 100 includes handle 110, and an elongate flexibleshaft, shaft 105, extending from handle 110. Attached to the distal endof shaft 105 is a radially expandable and/or compactable assembly,expandable assembly 130. In an alternative embodiment, expandableassembly 130 is mounted to (e.g. surrounding) a distal portion of shaft105, at a location proximal to the distal end of shaft 105. In someembodiments, expandable assembly 130 is constructed and arranged asdescribed in reference to applicant's co-pending U.S. patent applicationSer. No. 14/422,941, titled “System and Method for Diagnosing andTreating Heart Tissue”, filed Feb. 5, 2015, the content of which isincorporated herein by reference in its entirety. Shaft 105 andexpandable assembly 130 are constructed and arranged to be inserted intoa body (e.g. an animal body or a human body, such as the body of PatientP), and advanced through a body vessel, such as a femoral vein, jugularvein, or other blood vessel. Shaft 105 and expandable assembly 130 canbe constructed and arranged to be inserted through introducer 50, suchas when expandable assembly 130 is in a compacted state, and slidinglyadvanced through a lumen of shaft 55 into a body space, such as achamber of the heart, such as the right atrium or the left atrium, asexamples.

Handle 110 can include one or more controls, such as control 111.Control 111 can comprise a knob, switch, lever, button, slide, or othercontrol configured to perform a function selected from the groupconsisting of: steer the distal portion of shaft 105; control theexpansion and/or contraction of expandable assembly 130 such as byadvancing and/or retracting a control rod, not shown but such as isdescribed herebelow in reference to FIG. 5; control the shape ofexpandable assembly 130, such as by advancing or retracting a controlrod operably attached to expandable assembly 130; close and/or open anelectrical connection, such as to provide power to one or morecomponents of expandable assembly 130; initiate a process or otherwisesend a command or other user activated signal to electronics module 200;and combinations of these.

Expandable assembly 130 can comprise a structure including multipleflexible arms or splines, splines 131 a-c (singly or collectivelysplines 131), as shown. In some embodiments, expandable assembly 130 cancomprise between two and ten splines 131, such as six splines 131. Inthe embodiment of FIG. 1, three splines 131 a-c are equally spaced abouta central axis of catheter 100 (i.e., a spacing of 120° between eachspline when expandable assembly 130 is deployed in its expanded state).In other embodiments, splines 131 can be equally or unequally spaced,such as two, four, eight or twelve splines 131 with an equal spacing of180°, 90°, 60°, 45°, and/or 30°, respectively. In some embodiments,expandable assembly 130 can comprise a balloon, radially deployablearms, and/or other expandable and compactible structure.

Expandable assembly 130 can further comprise multiple “pairs” ofelectrical components, for example, at least one pair comprising anelectrode 132 and an ultrasound element, transducer 133. Each electrode132 can be configured to record a voltage, such as the voltage presenton a surface of the heart or at a location within a heart chamber. Eachultrasound transducer 133 can be configured to send and/or receiveultrasound signals, such as to produce an anatomical image of the tissueof at least a portion of the heart or other patient anatomical location.Electrodes 132 and ultrasound transducers 133 can comprise differentshapes, such as a shape selected from the group consisting of: round;triangular; rectangular; hexagonal; trapezoidal; and combinations of twoor more of these. In some embodiments, a first electrode 132 has asdifferent shape than a second electrode 132. In some embodiments, afirst ultrasound transducer 133 has a different shape than a secondultrasound transducer 133. In some embodiments, one or more ultrasoundtransducers 133 each comprise a single element or an array of elements(e.g. a microarray of ultrasound elements), for example an array ofultrasound elements configured as a phased array (e.g. to allow steeringand/or focusing of ultrasound energy). In some embodiments, one or moreultrasound transducers 133 comprise an element selected from the groupconsisting of: bulk ceramic (thickness-mode or spherical); micromachinedultrasound transducer (MUT), such as piezoelectric (pMUT) or capacitive(cMUT); thin film such as PVDF; shear-wave; and combinations of two ormore of these.

Each connected pair of an electrode 132 and an ultrasound transducer 133can share a single conductor (e.g. a wire or other communication and/orpower delivery conduit), such as communication path 134 (e.g. a wire)described herebelow. In some embodiments, multiple pairs of electrode132 and ultrasound transducer 133 can collectively share a singleconductor, communication path 135 (e.g. a wire), also as describedherebelow.

The embodiment of FIG. 1 shows three electrode/transducer pairs per eachspline 131 a-c (i.e. nine pairs for expandable assembly 130), each paircomprising an electrode 132 and an ultrasound transducer 133. Spline 131a comprises three electrode/ultrasound pairs, 132 _(i)/133 _(i)-132_(iii)/133 _(iii). Spline 131 b comprises three electrode/ultrasoundpairs. 132 _(iv)/133 _(iv)-132 _(vi)/133 ^(vi). Spline 131 c comprisesthree electrode/ultrasound pairs, 132 _(vii)/133 _(vii)-132 _(ix)/133_(ix). Each electrode/ultrasound pair 132/133 is electrically orotherwise operably connected to a connection point 136 via acommunication path 134, such as when splines 131 include a printedcircuit (e.g. a flexible printed circuit), and communication paths 134can comprise traces on the printed circuit, such as is described inreference to applicant's co-pending U.S. patent application Ser. No.14/762,944, titled “Expandable Catheter Assembly with Flexible PrintedCircuit Board (PCB) Electrical Pathways”, filed Jul. 23, 2015, thecontent of which is incorporated herein by reference in its entirety. Invarious embodiments, such as the embodiment shown in FIG. 1, one or moreelectrode/ultrasound pairs 132/133 can share a common communication path135, such as a trace configured as a common ground, electrically orotherwise operably connected to a connection point 136.

In the embodiment shown, a communication path 134 is connected to anelectrode 132, such as electrode 132 _(i), which is connected to thepositive terminal of a paired ultrasound transducer 133, such asultrasound transducer 133 _(i). The negative terminal of ultrasoundtransducer 133 _(i) is connected to common communication path 135. Insome embodiments, two or more electrode/ultrasound pairs 132/133 canshare a common communication path 135. In some embodiments, each spline131 can comprise two or more common communication paths 135, such as aspline comprising eight electrode/ultrasound pairs 132/133, comprisingtwo common communication paths 134, each shared by fourelectrode/ultrasound pairs 132/133.

A conduit comprising one or more electrical, optical, or electro-opticalwires or cables (e.g. coaxial wires), such as conduit 106, can provide acommunication path between one or more components of expandable assembly130, such as one or more electrode/ultrasound pairs 132/133, and handle110 of catheter 100. Conduit 106 terminates in handle 110 at connector116. Connector 116 can comprise a jack, plug, terminal, port, or othercustom or standard electrical, optical, or electro-optical connector.Conduit 106 can extend distally from handle 110, through one or morelumens of shaft 105, and terminate at the one or more connection points136. In some embodiments, conduit 106 can comprise multiple coaxialcables, configured to extend through multiple lumens within shaft 105,such as when conduit 106 comprises one coaxial cable perelectrode/ultrasound pair 132/133, and the coaxial shields areconstructed and arranged to provide a common communication medium (e.g.a ground wire). Two or more coaxial cables can be joined to share acommon communication medium, such as four or eight coaxial cables linkedto create a common channel. In some embodiments, a coaxial cable can beused that comprises a gauge greater than 36 AWG, such as 42 AWG or 46AWG, and can comprise a nominal impedance of less than or equal to 500,and a capacitance of approximately 110 pF/m at 1 kHz.

Electronics module 200 comprises one or more connectors 216, eachcomprising a jack, plug, terminal, port, or other custom or standardelectrical, optical, or electro-optical connector. System 10 cancomprise a cable or other conduit, such as cable 206, configured toelectrically, optically, and/or electro-optically connect catheter 100to electronics module 200 via connectors 116 and 216. In someembodiments, electronics module 200 can comprise a patient isolationcircuit 201, configured to electrically isolate one or more componentsof electronics module from Patient P (e.g. to prevent undesired deliveryof a shock or other undesired electrical energy to Patient P). Isolationcircuit 201 can be integral to electronics module 200 and/or it cancomprise a separate discrete component (e.g. separate housing).

System 10 can further comprise one or more surface electrodes 225, e.g.,such as patch electrodes configured to attach to the skin of thepatient. Surface electrodes 225 are electrically connected toelectronics module 200 via one or more electrical, optical or otherconduits, referred to as conduits 226. Surface electrodes can beconstructed and arranged to transmit and/or record signals to and/orfrom Patient P, such as when surface electrodes 225 transmit electricalsignals to generate one or more electrical fields within Patient P, suchas electrical fields used in a localization procedure as describedherein. In some embodiments, system 10 can be configured to generate oneor more images based upon information recorded using diagnostic catheter100, and to correlate cardiac or other electrical activity (e.g. voltageinformation, dipole information and/or surface charge information) tothe one or more images. Alternatively or additionally, system 10 can beconfigured to correlate cardiac or other electrical activity to one ormore images generated using imaging device 80.

Electronics module 200 comprises electrode transceiver circuitry 210,ultrasound transceiver circuitry 220, and user interface subsystem 230.Electrode transceiver circuitry (ETC) 210 comprises one or morecomponents selected from the group consisting of: a processor, such as acomputer processor configured to perform one or more calculations basedon data recoded from electrodes 132; at least one filter, such as one ormore filters configured to filter one or more data sets recorded fromelectrodes 132; at least one signal generator, such as signal generator211, configured to generate signals used to create a localization fieldas described herebelow; at least one memory module, such as a memorymodule configured to store data recorded from electrodes 132; andcombinations of these.

Ultrasound transceiver circuitry (UTC) 220 comprises one or morecomponents selected from the group consisting of: a processor, such as acomputer processor configured to perform one or more calculations basedon data recorded from ultrasound transducers 133; at least one filter,such as one or more filters configured to filter one or more data setsrecorded from transducers 133; at least one signal generator, such assignal generator 221, configured to generate signals used to drivetransducers 133 to cause an ultrasonic signal to be produced asdescribed herebelow; at least one memory module, such as a memory moduleconfigured to store data recorded from transducers 133; and combinationsof these. However, in some embodiments, the ETC 210 and UTC 220 canshare components, such as sharing one or more processors and/or one ormore memory module.

User interface subsystem 230 can comprise one or more user input and/oruser output components, such as one or more components selected from thegroup consisting of: a keyboard; a mouse; one or more buttons orswitches; a monitor; a touch screen; a speaker; a microphone; a footpedal; a printer; a transmitter, a receiver, and combinations of these.User interface subsystem 230 can be configured to allow user input, suchas to set one or more parameters associated with the operation of system10. User interface subsystem can be further configured to displayinformation to a user, such as information selected from the groupconsisting of: electrical cardiac activity information (e.g., dipoledensity, surface charge density, and/or voltage information, such as,voltage information measured and recorded from electrodes 132 and/ordipole or surface charge density information calculated from datarecorded from electrodes 132); device localization (position) data, suchas data calculated from data recorded from electrodes 132 and/or otherelectrodes of system 10; cardiac geometry data, such as geometry datacalculated from signals provided by ultrasound transducers 133; one ormore images, such as one or more images recorded from imaging device 80and/or one or more images generated by electronics module 200 (e.g. fromdata provided by ultrasound transducers 133), such as a text orgraphical representation of one or more calculated values by ETC 210and/or UTC 220; and combinations of these.

In some embodiments, system 10 can comprise a system constructed andarranged to determine a dipole density map correlating to thedistribution of dipole densities on the wall of a heart chamber, and/ora surface charge density map correlating to the distribution of surfacecharge densities on the wall of a heart chamber such as the systemdescribed in applicant's U.S. Pat. No. 8,512,255, titled “Device andMethod for the Geometric Determination of Electrical Dipole Densities onthe Cardiac Wall”, filed Aug. 31, 2012, the content of which isincorporated herein by reference in its entirety. Alternatively oradditionally, system 10 can comprise a system constructed and arrangedto determine a voltage map, or other diagnostic data set of electricalor anatomic information recorded by catheter 100 and/or calculated byelectronics module 200.

Electrodes 132 can be configured to record electrical activity of theheart chamber, such as by biopotentials (voltages) representing theelectrical activity of the heart. Electrodes 132 can be furtherconfigured to perform a localization process, comprising recording avoltage caused by an electrical field, such as a localization fieldgenerated by surface electrodes 225. Electronics module 200 andultrasound transducers 133 can be configured to perform anultrasonically-based distance measurement, comprising transmittingultrasonic signals from one or more ultrasound transducers 133, andhaving similar or dissimilar ultrasound transducers 133 record at leastthe first reflections of the transmitted signals.

ETC 210 can be configured to process data recorded by electrodes 132 toproduce information selected from the group consisting of: the locationof individual electrodes 132; the location, current geometry and/ororientation of expandable assembly 130 and its respective components (byprocessing recorded localization data); the location of one or moreadditional components or devices present within the heart chamber;electrical activity of a heart chamber, such as dipole density orsurface charge density on the wall of the heart chamber or voltages, byprocessing recorded biopotential data; and combinations of these.

UTC 220 can be configured to process recorded ultrasound reflection datafrom ultrasound transducers 133 to produce information selected from thegroup consisting of: distance from a transducer 133 to a first surfaceof a heart chamber; distance from an ultrasound transducer 133 to asecond surface of a heart chamber; distance between a first surface of aheart chamber and a second surface of a heart chamber (e.g. a heart wallthickness comprising the distance between the endocardial surface andepicardial surface of a heart chamber); location of one or more anatomicfeatures, such as the pulmonary veins (e.g. pulmonary vein ostia);location of a cardiac valve; other anatomic geometry information; tissuevelocity; tissue density; distance from a transducer 133 to a surface ofanother component of system 10; and combinations of these.

In some embodiments, a single component (e.g. only a single electrode132 or a single ultrasound transducer 133) of an electrode132/ultrasound transducer 133 pair is “activated” at a time (e.g., isprovided a signal by electronics module 200 or has its signal recordedby electronics module 200). For example, during the activation period ofan ultrasound transducer 133 (e.g. comprising ringing, ringing down,and/or recording), the recording and/or driving of its paired electrode132 can be disabled (e.g. not performed or ignored). Alternatively,during the activation of an electrode 132 (e.g. driving and/orrecording), driving or recording of a paired ultrasound transducer 133can be disabled (e.g., not performed or ignored). Isolation oractivation of either an electrode 132 or an ultrasound transducer 133 ofa connected pair can prevent issues that can be caused by an ultrasoundtransducer 133 drive signal interfering with a localization drive signal(e.g. provided by a surface electrode) and/or a biopotential signalrecorded by an electrode 132. In some embodiments, one or more recordedsignals are filtered, allowing for simultaneous operation of ultrasoundprocessing and biopotential processing. In some embodiments, system 10can comprise a standard diagnostic mode, comprising performingbiopotential measurements continuously, and interleaving a localizationprocess and an ultrasound measurement process, such as process 500described in reference to FIG. 2 herebelow. Ultrasound signals caninterfere with biopotential signals, and/or biopotential signals caninterfere with localization signals. In some embodiments, one or moreprocesses (localization, ultrasound, and biopotential measurements) canbe interleaved with one or more other processes, such that an individualprocess (or combination of processes) does not cause interference with aseparate process (or combination of processes).

During an operational mode, such as a diagnostic mode as described inFIG. 2 herebelow, the activation period of a transducer 133 causes a“blanked” period for paired electrode 132, causing a temporary “blindspot” of biopotential measurement. As described in reference to FIG. 4herebelow, a sequencing of transducers 133 can be performed, such thatthe temporary “blind spot” is not extended by sequentially activatingadjacent or otherwise proximate pairs 132/133.

In some embodiments, a sequence is performed as follows. During anultrasound measurement process, all electrodes 132 can actively recordbiopotential signals. A first transducer 133 _(i) can be activated, asdescribed herebelow in reference to FIG. 4, causing a “blanking” ofpaired electrode 13Z. Following the activation of transducer 133 _(i),transducer 133 _(v) can be activated, followed by 133 _(ix), 133 _(ii),133 _(vi), 133 _(viii), 133 _(iii), 133 _(iv), and 133 _(vii). In thisembodiment, the “blind spot” created by the “blanking” of pairedelectrodes 132 follows the same pattern, moving non-sequentially aboutexpandable assembly 130, and minimizing any potential data integrityloss due to the blind spots created.

In some embodiments, system 10 comprises one or more sensors, eachconfigured to produce a signal, such as sensor 59 of introducer 50, asensor of diagnostic catheter 100 (e.g. sensor 119 of handle 110 orsensor 139 of array 130), a sensor 209 of electronics module 200 and/ora sensor 89 of imaging device 80, each as shown in FIG. 1. In someembodiments, system 10 comprises two or more of sensors 59, 119, 139,209 and/or 89. In some embodiments, sensors 59, 119, 139, 209 and/or 89comprise a sensor selected from the group consisting of: a force sensor;a pressure sensor; a strain gauge; an optical sensor; an imaging sensor(e.g. a lens or optical fiber); a sound sensor such as an ultrasoundsensor; a hall effect sensor; a pH sensor; a magnetic sensor; atemperature sensor; and combinations of one or more of these. In someembodiments, sensors 59 and/or 139 comprise a patient physiologicsensor, such as a sensor selected from the group consisting of: a bloodpressure sensor; a blood gas sensor; a temperature sensor; a bloodglucose sensor; a pH sensor; a respiration sensor; an average clottingtime (ACT) sensor; and combinations of one or more of these. In someembodiments, system 10 is configured to analyze a signal produced byone, two or more of sensors 59, 119, 139, 209 and/or 89. In someembodiments, system 10 (e.g. electronics module 200 and/or an algorithmof ETC 210) is configured to perform an analysis of one or more signalsproduced by one, two or more of sensors 59, 119, 139, 209 and/or 89 incombination with voltage data, dipole density data, surface charge data,and/or anatomical data (e.g. anatomical data collected by one or moreultrasound transducers 133). In some embodiments, signals from one ormore sensors 59, 119, 139, 209 and/or 89 are used by system 10 toperform a function selected from the group consisting of: improve ananatomical image displayed by system 10; improve cardiac informationdisplayed by system 10 (e.g. dipole density and/or surface chargeinformation); detect a malfunction of system 10; provide physiologicdata of a patient; and combinations of one or more of these. In someembodiments, one or more of sensors 59, 119, 139, 209 and/or 89 cancomprise a transducer (e.g. as an alternative to being a sensor or inaddition to being a sensor), such as a transducer selected from thegroup consisting of: a heating element; a cooling element; a vibratingelement; a drug or other agent delivery element; a magnetic fieldgenerating element; a light delivery element; an imaging element (suchas a lens, and/or optical fiber); and combinations of one or more ofthese.

Referring now to FIG. 2, provided is an embodiment of a method ofperforming a diagnostic assessment, consistent with the presentinventive concepts. In some embodiments, process 500 of FIG. 2 isaccomplished using system 10 of FIG. 1 described hereabove. In STEP 510,a diagnostic catheter 100 is inserted into a heart chamber of a patientP. Further processes can be performed in order to prep the patient for adiagnostic procedure, such as a process selected from the groupconsisting of: applying one or more surface electrodes 225 to thepatient; preparing one or more alternate imaging devices, such asimaging device 80 described hereabove; delivery of one or more drugs orother agents to the patient, such as a heart medication or bloodthinner; preparing ETC 210 for use; and combinations of two or more ofthese.

In STEP 520, the system 10 is placed in a diagnostic mode. Thediagnostic mode can be configured to produce one or more images or setsof information correlating to the anatomical shape and/or configurationof a heart chamber, and/or the electrical activity of a heart chamber,such as mapping information gathered prior to and/or during a cardiacablation procedure. The diagnostic mode can comprise STEPS 530, 540, and550, performed repeatedly, simultaneously, or in a particular pattern,as described herein.

In STEP 530, system 10 performs an analysis of biopotential data,determining dipole, surface charge and/or other voltage or charge basedinformation correlating to the electrical activity of the heart, such asdescribed in U.S. Pat. No. 8,417,313, entitled “Method and Device forDetermining and Presenting Surface Charge and Dipole Densities onCardiac Walls,” which is incorporated herein by reference. Electrodes132 are electrically connected to ETC 210 of electronics module 200 viaconduits 106 and cables 206. ETC 210 can comprise one or more algorithmsfor determining dipole density and/or surface charge based on datarecorded from electrodes 132. ETC 210 can further comprise one or morefilters (e.g. hardware or software filters), configured to pass (e.g.not significantly filter) biopotential signals, while filtering othersignals, specifically ultrasound and/or localization signals presentwithin the chamber of the heart or otherwise within Patient P. In someembodiments the processes of STEP 530 can be continuously performedduring the completion and/or repetition of STEPS 540 and 550, such ascontinuously while system 10 remains in a diagnostic mode.

In STEP 540, a localization process is performed, such as a localizationprocess described below with reference to FIG. 3.

In STEP 550, an ultrasound measurement process is performed, such as anultrasound measurement process described below in reference to FIG. 4.

In Step 560, if system 10 remains in a diagnostic mode, STEPS 530, 540,and 550 are repeated. In some embodiments, such as when STEP 530 iscontinuously performed while system 10 remains in a diagnostic mode,STEPS 540 and 550 are repeated continuously while system 10 remains in adiagnostic mode. In some embodiments STEP 540 can be performed forlonger, or multiple times for a single STEP 550. In some embodimentsSTEP 550 can be performed for longer, or multiple times for a singleSTEP 540.

System 10 can be placed in an alternate mode, such as a mode selectedfrom the group consisting of: a hold mode, such as a mode when catheter100 remains inserted in Patient P, however diagnostic procedures are notperformed; an alert mode, such as a mode when system 10 has detected anerror and diagnostic and/or other procedures are halted; ashutdown/completion mode, such as a mode when system 10 is deactivated,such as to be removed from Patient P at the end of a diagnostic ortreatment procedure. In STEP 560, when system 10 is determined to nolonger be in a diagnostic mode, process 500 enters STEP 570. In STEP570, all diagnostic procedures are stopped.

In some embodiments, system 10 can alternate between STEP 540 and STEP550, such as to gather localization information and ultrasoundinformation to generate a model of the anatomy of the heart.Subsequently, STEP 530 and STEP 540 can be performed, alternatingly orsimultaneously, such as to map the electrical activity of the heart,such that system 10 can register the mapped electrical activity to themodeled anatomy gathered previously. In some embodiments, system 10 canagain alternate between STEP 540 and STEP 550 to update the model of theanatomy.

Referring now to FIG. 3, provided is an embodiment of a method ofperforming a localization process, consistent with the present inventiveconcepts. In some embodiments, process 600 of FIG. 3 is accomplishedusing system 10 of FIG. 1 described hereabove. In STEP 610, system 10begins a localization process. In some embodiments this process can beinterleaved with an ultrasound measurement process as described belowwith reference to FIG. 4.

In STEP 620, signal generator 211 generates one or more localizationsignals, transmitted to patient P through one or more surface electrodes225 via conduits 226. Surface electrodes 225 can comprise one or morepairs of electrodes 225, such as three pairs of electrodes 225,configured to provide a three axis localization system. For example, ina three axis localization configuration, pairs of surface electrodes 225can be placed on patient P; a first pair placed on the chest and back ofpatient P defining a first, X axis; a second pair placed laterally onthe sides of patient P defining a second, Y axis; and a third pairplaced on the neck or shoulder and thigh of patient P, defining a third,Z axis. Alternatively, a first pair of electrodes can be placedlaterally on the sides of the patient defining a first axis, a secondpair of electrodes can be placed on the upper chest and lower back ofthe patient defining a second axis, and a third pair of electrodes canbe placed on the upper back and lower chest of the patient, defining athird axis. In some embodiments, signal generator 211 generates 3 ormore signals of different frequencies, such as to drive three or moreaxes (e.g. each axis X, Y, and Z described hereabove), each at a uniquefrequency. The three or more axes can comprise two or more axes that areorthogonal to each other. Alternatively or additionally, signalgenerator 211 can generate 3 signals which differ in phase or othermeasurable characteristics, such that each signal (axis) can bedetermined via filtering to perform multi axis localization as describeherebelow. In some embodiments, each axis is powered individually (e.g.one at a time), and single axis localization can be interleaved betweenone or more desired axes. In the embodiment of process 600, STEP 620 canbe performed continuously, throughout process 600, or throughout adiagnostic procedure (e.g. localization signals are continuously driventhroughout the diagnostic procedure).

In STEP 630, ETC 210 records data collected from one or more electrodes132, such as from each electrode 132 simultaneously or sequentially. InSTEP 640, the recorded data can be filtered one or more times, such asby one or more sequential filters and/or one or more parallel filters.In an embodiment, the recorded data can be initially filtered to isolatesignals correlating to the localization signals generated by generator211, such as signals comprising a frequency between 1 and 100 kHz, suchas between 10 and 100 kHz. The filtered data can subsequently be splitand filtered by multiple (e.g. three) parallel filters, each configuredto isolate a single frequency range, such as a frequency rangeassociated with a single axis.

In STEP 650, the three sets of individually filtered data can beanalyzed, for example by a localization algorithm, such as to determinethe location of each electrode 132, in a three dimensional coordinatesystem relative to Patient P. In some embodiments, localization process600 can comprise the use of more or fewer axes, such as two, three, orfour axes. Additionally or alternatively, localization process 600 cancomprise the use of concentric surface electrodes 225. Localizationprocess 600 can comprise multiple filters and/or multiple data pathswithin ETC 210, such as multiple data paths corresponding to multipleaxes, and multiple levels of data filtering.

In STEP 660, if system 10 remains in a localization process, STEPS 620through 650 are repeated. In some embodiments system 10 can remain in alocalization process for a time period between 1 μs and is, such asbetween 50 μs and 0.5 s, such as approximately 10 ms, for example whenlocalization process 600 is interleaved with an ultrasound measurementprocess and each process is performed during similar or dissimilaramounts of time. In STEP 660, when system 10 is determined to no longerbe in a diagnostic mode, process 600 enters STEP 670. In STEP 670, thelocalization 600 process is stopped.

Referring now to FIG. 4, provided is a method of performing anultrasound measurement process, consistent with the present inventiveconcepts. In some embodiments, process 700 of FIG. 4 is accomplishedusing system 10 of FIG. 1 described hereabove. In STEP 710, system 10begins an ultrasound measurement process. In some embodiments thisprocess can be interleaved with a localization process as described inreference to FIG. 3 hereabove.

In STEP 720, UTC 220 “activates” a first transducer 133 (which can bereferred to as 133 _(FIRST)), such as by closing one or more switches,electrically connecting the first transducer 133 _(FIRST) to generator221 and/or other electrical components of UTC 220, such as is describedin reference to FIG. 6 herebelow. In some embodiments, the one or moreswitches can comprise an opto-coupler, such as an opto-coupler with anactivation time of approximately 0.01 μs, or approximately 500 μs.Generator 221 can be configured to generate a pulsed “drive signal”,configured to “ring”, vibrate, and/or otherwise cause transducer 133 togenerate an ultrasonic pulse. The drive signal can comprise a signalwith one or more frequencies between 1 MHz. and 25 MHz, such as a drivesignal with at least a frequency of approximately 10 MHz. The drivesignal can further comprise a signal comprising a pulse width between0.1 μs and 10 μs, such as a pulse width of approximately 1.0 μs or 2.0μs.

In some embodiments, such as the paired electrode/transducer embodimentof FIG. 1, the activation of a transducer 133 causes the deactivation ofits paired electrode 132. During the activation period of a transducer133, ETC 210 does not record electrical signals received by the pairedelectrode 132, causing a temporary “blind spot”. As described herebelow,a non-sequential sequence of transducers 133 can be activated, such thatthe temporary “blind spot” in electrical recording is not extended bysequentially activating adjacent pairs 132/133.

In STEP 730, first transducer 133 _(FIRST) remains activated, however isno longer being driven by generator 221. Transducer 133 “rings down” (oris “rung down”), such as to allow all driven vibration of firsttransducer 133 _(FIRST) to cease and any remnant vibrations within firsttransducer 133 _(FIRST) to dissipate. In some embodiments, STEP 730 cancomprise a duration of between 0.05 μs and 1 μs, such as a duration ofapproximately 0.1 μs.

In STEP 740, UTC 220 is configured to “listen”, such as by recording anyultrasonic vibrations sensed by first transducer 133 _(FIRST) andrecording reflections of one or more ultrasonic pulses generated in STEP720. These reflections can correlate to reflections of ultrasound off offeatures or structures selected from the group consisting of: an innerwall of the cardiac chamber; an outer wall of the cardiac chamber; afeature of the cardiac chamber, such as a pulmonary vein or cardiacvalve; a portion of a device inserted into the cardiac chamber, such asan ablation catheter and/or second mapping catheter also inserted intothe cardiac chamber; and combinations of two or more of these. In someembodiments, STEP 740 can be configured to “listen” for reflectionsduring a time period of between 1 μs and 200 μs, such as a time periodof approximately 100 μs. UTC 220, or another component of electronicsmodule 200, can be configured to determine a distance measurement, suchas a measured distance from first transducer 133 _(FIRST) to the sourceof the first received reflection, such as a reflection from the innerwall of the cardiac chamber. The distance measurement can be determinedusing techniques commonly known to those skilled in the art, such as bydetermining the total “travel time” of the ultrasonic pulse, and usingthe speed of sound in blood and/or other tissue (as appropriate) todetermine the total travel distance of the pulse.

In STEP 750 a subsequent transducer, 133 _(NEXT) can be electronicallyprepared. Preparation can include “activating” transducer 133 _(NEXT),as described hereabove. STEP 750 can further comprise the deactivationof the previous transducer 133 _(PREV), for example transducer 133_(FIRST). In some embodiments, activation of transducer 133 _(NEXT) cancomprise a process requiring a duration of between 0.01 μs and 500 μs,such as a duration of approximately 50 μs. In these embodiments, theactivation of transducer 133 _(NEXT) can be interleaved with adeactivation of the previous transducer 133 _(PREV), and/or with aportion of STEP 740, such that transducer 133 _(NEXT) is being activatedwhile transducer 133 _(PREV) is listening and or being deactivated. Insome embodiments, these processes can overlap for a time period ofbetween 0.01 μs and 500 μs, such as a time period of approximately 100μs. In some embodiments, the duration from the start of an activationprocess of a transducer 133 to the end of a deactivation process can bebetween 1 μs and 700 μs, such as a duration of approximately 200 μs.

In STEPS 760 through 780, transducer 133 _(NEXT) is rung, rung down, andlistened to and recorded, as described in reference to STEPS 720 through740 hereabove.

In STEP 790, if all transducers 133 (or a predetermined subset thereof)have not been activated since the start of process 700, STEPS 750through 790 are repeated. In some embodiments, a subset of transducers133 are activated per process 700, such as approximately half orapproximately one third of the transducers 133, such as when two orthree cycles of process 700 are required to activate all transducers133, such as two or three cycles run sequentially or are interleavedwith one or more other processes, such as process 600 of FIG. 3. In someembodiments, a complete cycle, such as a cycle in which all transducers133 are activated, can comprise a duration of between 500 μs and 10,000μs, such as a duration of approximately 5,000 μs. In the embodiment ofFIG. 5 described herebelow, catheter 100 can comprise 48 transducers133. Each activation period can comprise a duration of approximately 200μs, and process 700 can comprise a duration of approximately 5 ms.

In STEP 790, if all transducers 133 (or a predetermined subset thereof)have been activated, process 700 continues to STEP 795. In STEP 795, ifthe measurement process is to be repeated, for example if a subsequent(similar or dissimilar) subset of transducers 133 is to be activated,STEPS 720 through 790 are repeated. If the measurement process iscompleted, process 700 enters STEP 799. In STEP 799, the measurementprocess is stopped.

Referring now to FIG. 5, provided is a perspective view of an embodimentof a diagnostic catheter that includes expandable assembly 130,consistent with the present inventive concepts. The expandable assembly130 can be, in whole or in part, in accordance with the description ofU.S. patent application Ser. No. 14/762,944, entitled “ExpandableCatheter Assembly with Flexible Printed Circuit Board (PCB) ElectricalPathways”, filed Jul. 23, 2015, which is incorporated herein byreference. In the embodiment of FIG. 5, the expandable assembly 130includes a plurality of splines 131 configured as shown (i.e., sixsplines, radially separated by 60°, each spline comprising eightelectrode transducer pairs 132/133). In this embodiment, transducers 133are coupled to splines 131 using a housing 138. In other embodiments,multiple transducers 133 can be coupled to splines 131 (e.g. between twoand twelve splines 131) in different manners.

In this embodiment, an array of transducers 133 and electrodes 132 aresubstantially equally distributed across splines 131, as shown in theexpanded state of expandable assembly 130. Proximal ends (nearest shaft105) of splines 131 are attached to a distal portion of shaft 105, suchas at a location in and/or within shaft 105, or between shaft 105 and aninner, translatable (i.e. advanceable and retractable) shaft, controlrod 107. Control rod 107 can comprise one or more conduits and/orpassageways, such as lumen 108 as shown. Lumen 108 can be configured toallow for catheter 100 to be inserted over a guidewire, such as whenlumen 108 is sized to slidingly receive a guidewire, and lumen 108continues to a proximal portion of catheter 100, such as when lumen 108exits handle 110 of catheter 100. Additionally or alternatively, lumen108 can be sized to slidingly receive one or more devices such as adevice selected from the group consisting of: an ablation catheter; amapping catheter; a cryo ablation catheter; a tip ablation catheter; adiagnostic catheter; and combinations of two or more of these. In so ryeembodiments, lumen 108 can be configured to allow for the delivery ofone or more drugs or other agents during a diagnostic or otherprocedure.

In some embodiments, electrodes 132 can be positioned on the inside ofsplines 131. Alternatively or additionally, electrodes 132 can comprisesome electrodes positioned on the inside of splines 131 and someelectrodes positioned on the outside of spline 131. Alternatively oradditionally, electrodes 132 can be double sided electrodes, withopposing surfaces facing both inward and outward of the basket, orelectrodes 132 can comprise ring-shaped electrodes, surrounding eachspline 131 respectively.

As shown, distal ends of splines 131 are connected to the distal end ofcontrol rod 107. Control rod 107 can be advanced and retracted tocompact and expand, respectively, expandable assembly 130. Control rod107 can be advanced and retracted via a control on a proximal handle,such as control 111 on handle 110 of FIG. 1. In some embodiments,control rod 107 can be retracted from a position correlating to thenatural expanded position of expandable assembly 130 (as shown byexample in FIG. 5), such as to deform expandable assembly 130, such asto invert a distal portion of splines 131, resulting in at least thedistal most transducers 133 aligning in a forward facing direction, asshown in FIG. 5A. In this configuration, the forward facing transducers133 can be used as an array of transducers to perform B mode scans, orother ultrasound scanning methods known in the art.

As described herein, expandable assembly 130 of FIG. 5, including fortyeight electrode/transducer pairs 132/133, can be used to performbiopotential measurements, localization measurements, and/or ultrasounddistance measurements. During an ultrasound measurement process, such asprocess 700 of FIG. 4 described hereabove, transducers 133 of expandableassembly 130 of FIG. 5 can be sequenced as described herebelow inreference to FIG. 6.

Referring now to FIG. 6, a representation of an activation sequence ofan array of 48 ultrasound transducers disposed on six splines (8 perspline) is illustrated, consistent with the present inventive concepts.FIG. 6 is a particular representation of an activation sequence,representing a specific number of transducers, substantially equallyspaced across a specific number of splines on an expandable assembly,such as expandable assembly 130 of FIG. 5 hereabove. Alternatively,expandable assembly 130 can have different numbers of transducers and/orsplines, and a similar or dissimilar non-sequential sequence oftransducer activation can be performed.

In the embodiment of FIG. 6, transducers 1-8 represent a most distal (1)transducer through a most proximal transducer (8), across each of sixsplines. Each activation period depicted by a solid box represents aperiod of activation and as described herein, a deactivation or blankingof a paired electrode. The pattern shown represents a pattern avoidingthe sequential activation of two neighboring transducers, such as apattern avoiding the sequential activation of two transducers within twoor three “neighboring spaces” of each other. Neighboring spaces can beconsidered spaces on a single spline; across splines, such as transducer1 of spline 1 and transducer 1 of spline 2; and/or diagonally acrosssplines, such as transducer 1 of spline 1 and transducer 2 of spline 2.The pattern shown also represents a pattern avoiding sequentialactivation of two transducers from a single spline.

FIG. 7 provides an embodiment of a block diagram of a user interface(UI) system 230 that can be used with a diagnostic catheter as describedherein, for example, in accordance with the present inventive concepts.

The UI system 230 includes a display area 240, which can include one ormore windows, screens, and/or monitors on which information can berendered/shown, e.g., as 2D or 3D displays. The windows in the displayarea 240 need not be arranged nor relatively sized as shown in FIG. 7.And not all windows shown in display area 240 must be included. Thedepiction in FIG. 7 represents an illustrative embodiment, but a UIsystem in accordance with the inventive concept is not limited to theparticular embodiment shown.

A 3D display window 242 can be included to show graphical elements in athree-dimensional (3D) space, such as a heart or heart chamber. Theimages and information rendered in the 3D display window 242 can changebased on the user task being performed, e.g., based on the task beingdone in a main application window 250. The 3D display window 242 canalso exist within the main application window 250, in some embodiments.The 3D display window 242 can be user interactive, and can change inresponse to the user interaction therewith.

A two-dimensional (2D) display window 244 can be included to showgraphical elements in a two-dimensional space. The images andinformation rendered in the 2D window 244 can change based on the usertask being performed, e.g., based on the task being done in the mainapplication window 250. The 2D display window 244 can also exist withinthe main application window 250, in some embodiments. The 2D displaywindow 244 can be user interactive, and change in response to the userinteraction therewith.

The main application window 250 can include the primary workflowinterface to create 3D maps. An acquisition window 252 provides tools,e.g. user interface tools, necessary to view and record biopotentialsignals, localization signals, and/or ultrasound signals. One tool ofthe acquisition window 252 allows ultrasound and localization data to becombined to reconstruct a chamber anatomy (i.e. build a digital model ofa surface that represents the chamber anatomy). This representation ofthe anatomy can be displayed in a surface building window 254.Additionally, previously reconstructed chamber anatomies (e.g. of thepatient and/or a surrogate) can be loaded from one or more datarepositories, such as files, databases, or memory and displayed in thesurface building window 254 to be used with live data. Configurationsettings are available from this window 254 to properly register/orienta chamber reconstruction to the live data.

A waveform processing window 256 can be provided and used to allowrecorded data to be reviewed, filtered, and/or analyzed. The user canuse these tools to identify a time segment of data to be mapped.Segments can be from 1 sample in length to the full recorded datalength. Segment selection can also take the form of passing datadirectly, time sample by time sample, to the mapping algorithm such thatmaps can be made “on the fly” (e.g. in real-time or near real-time, orpseudo real-time, “real-time” herein), without manual segment selection.The waveforms being processed can be shown in the 2D display window 244,e.g., in the form of an electrogram (EGM) or electrocardiogram (ECG orEKG). The 3D display window 242 can show any or all of the following:the voltage signals on the basket electrodes rendered onto athree-dimensional surface of the size and shape of the basket, a coloredtopographic surface showing the electrode signals (color and “Z-height”of the topography corresponding to voltage amplitude), with electrodesoriented in relative neighbor relationship, and/or the spatial positionof the basket in relation to the reconstructed surface to show thebasket position within the chamber of interest.

A mapping window 258 can be provided and used to allow configuration andexecution of the mapping algorithms, including selection of a surfacesource model. The resulting 3D maps can be rendered in the 3D displaywindow 242 with corresponding waveforms shown in the 2D display window244. A time cursor or window can be included to provide a time indexbetween display windows. The time cursor or window can be configured toslide or move across the waveforms in the 2D window in synch with adynamically changing display rendered in the 3D window.

A system configuration and diagnostic window 246 can be provided andused to show live signals from the catheters (e.g., processed throughelectronics module 200)—biopotential, localization, and/or ultrasound,as examples. This window 246 can be used for verification of operationof such systems or subsystems.

A surface editing window 248 can be provided and used to allow the userto edit and process the reconstructed anatomy. Tools provided caninclude but are not limited to: selection (individual vertices/polygons,rectangular, elliptical, free-form shape, automatic isolated componentselection and/or sharp feature selection), trimming (through-cut,front-surface cut), smoothing, re-meshing, hole-filling, sub-division,and surface deformation, such as push-pull, tools. These tools caninclude shape identification, component identification, isolation,extraction, appending and/or merging tools. These tools can be userinteractive surface editing tools. These tools can be configured tooperate manually, semi-automatically and/or automatically.

A user input module 260 can include human interface devices, such asmouse, keyboard, touchscreen, digital pen, or other devices that can beused to provide user input to and/or control of the system and itsrenderings.

FIGS. 8A-80 provide different views relating to the output of the userinterface system, in accordance with aspects of the present inventiveconcepts.

Referring to FIG. 8A, a point cloud (PointCloud) data structure isshown, which can be rendered in the 3D display window 242. According tothis embodiment, the 3D coordinate space is divided into sphericalsectors with quadrilateral cross-sections, except the poles which areN-sided. The cross-section of each bin at the same radius from theorigin is configured to be similar in area. Surface point coordinatesfall into one and only one bin, so do not overlap. Bin size, e.g.,subtended azimuth or elevation angle, can be configurable (e.g. oninstantiation). To change bin-size (and thus mesh size) and/ordisplacement of the surface relative to the center of the sphericalbins, all surface points in an existing PointCloud can be placed into asecond data structure with the desired parameters in one bulk operation.

A surface representative of the surface points in the data structure isdisplayed by merging all representative points or surface of each bin.In one embodiment, the representative vertices can be drawn with theinterconnecting mesh between bins to form the surface. As points areadded to the data structure, bins will be updated and the representativesurface is updated correspondingly. Bins with no points within them canbe hidden from display.

Referring to FIG. 8B, a PointCloud bin is shown and described withreference to a 3D rendering of a heart. All data points falling in eachbin are analyzed to determine a representative point (vertex) or surface(surface patch) for the bin. In one embodiment, the centroid of allpoints in the bin is used as a representative vertex. Data within eachbin can be assessed for quality, and vertices or polygons of therepresentative surface can be colored to indicate quality of the data.In one embodiment, the dispersion or radial distance variance in thedata can indicate the detection of a cardiac valve, vein, or otherradially-oriented anatomical structure.

Referring to FIG. 8C, a subset of neighboring bins are shown, and theirrelationships illustrated, where each bin is represented by a block. Anon-manifold interconnecting mesh is calculated between neighboringbins. The orientation relationship of bins is static to avoidtime-consuming recalculation of the non-manifold interconnecting meshbetween neighbors.

FIG. 9 provides an embodiment of a functional block diagram of a cardiacinformation processing system 900, in accordance with the presentinventive concepts.

Using the described system from FIG. 9, a user can choose what tocalculate and/or what to display, e.g., the user can display DipoleDensity (DDM), Charge Density (CDM), or Voltage (V-V). This informationis calculated based on information represented in the top three boxes902, 904, 906, e.g., the position of the electrodes 902, the shape andlocation of the chamber (surface) 904, and the potentials recorded atthe electrodes 906. The system can also be configured to support andenable changes back and forth between the different display modes, andwith post processing tools, can change how that information isdisplayed.

The processing includes selecting a forward model 908. Based thereon,one of the following three operations can be performed: Dipole DensityMapping (DDM) 910, Charge Density Mapping (CDM) 912, and/or Voltage toVoltage Mapping (V-V) 914. In Dipole Density Mapping (DDM), electricalfields that could be measured by electrodes inside and/or outside of theheart chamber are generated from a distribution of dipole sources,having a magnitude and direction, on the surface of the heart chamber,organized and arranged as Dipole Densities (DD). In Charge DensityMapping (CDM), electrical fields that could be measured by electrodesinside or outside of the heart chamber are generated from a distributionof scalar charge sources, having a magnitude only, on the surface of theheart chamber, organized and arranged as Charge Densities (CD). And inVoltage to Voltage Mapping (V-V), no source assumption is made, and thevoltages measured on electrodes inside or outside of the heart chamberare propagated from the voltages on the heart chamber surface (e.g.using Laplace's equation and/or other methods known to those skilled inelectromagnetic field theory).

With the chamber surface and electrodes' positions registered with thesurface as the inputs, the transform matrix, which encodes relationshipsbetween the DD/CD/Voltages on the heart chamber to the measured voltageson electrodes, is the output of the forward calculation.

An Inverse Calculation 916 is performed, with the potentials acquiredfrom the mapping catheter and the transform matrix (the output from theforward calculation) as the inputs, the DD/CD/Voltages on the surfacecan be obtained by solving a linear system using a regularizationmethod, for example the Tikhonov regularization method.

DD/CD/Voltages on the surface 920 are outputs from the inversecalculation 916. The surface voltages can be forwardly computed from thederived surface DD/CD for DDM/CDM, and surface voltages from V-V can beused to derive the surface DD/CD using the transform matrix specified bythe heart chamber surface.

In some embodiments, cardiac information processing system 900 comprisespost-process tool 930. Using the same, DD/CD/Voltages can bepost-processed to produce a Coulombian map (an adaptation of thediscrete Laplacian, or spatial second derivative of the DDM, CDM and/orVoltage maps), IsoChrone map (activation timings), Magnitude map (peakto peak magnitude or negative peak magnitude), Persistence map (activeand resting status), and/or Propagation map (the wavefront), asexamples.

The 3D Display 242 can be used to display the outputs from thepost-processing tools 930. That is, for example, surface DD/CD/Voltages,as well as post-processing maps, can be rendered by selecting options onthe display panel of Dl system 230. The 3D maps can be rotated todifferent viewing angles and a color map can be adjusted by a user, asexamples.

While the foregoing has described what are considered to be the bestmode and/or other preferred embodiments, it is understood that variousmodifications can be made therein and that the invention or inventionsmay be implemented in various forms and embodiments, and that they maybe applied in numerous applications, only some of which have beendescribed herein. It is intended by the following claims to claim thatwhich is literally described and all equivalents thereto, including allmodifications and variations that fall within the scope of each claim.

We claim:
 1. A body cavity imaging system, comprising: a catheterconfigured for delivery to a body cavity defined by surrounding tissue;a plurality of ultrasound transducers coupled to a distal end of thecatheter, wherein the plurality of ultrasound transducers are disposedon a plurality of splines of a 3D array; and a plurality of biopotentialelectrodes disposed on the plurality of splines of the 3D array, whereina biopotential electrode and an ultrasound transducer are disposedtogether to form an electrode/transducer pair, and the system includes aplurality of electrode/transducer pairs; and an electronics moduleconfigured to selectively turn on/off each ultrasound transduceraccording to a predetermined activation sequence and to process signalsreceived from each ultrasound transducer to produce a 3D display of thesurrounding tissue, wherein the activation sequence comprises a patternof turning on/off transducers from the plurality of ultrasoundtransducers over a plurality of activation periods, wherein neighboringultrasound transducers are not sequentially activated in two consecutiveactivation periods on a single spline, across splines, and/or diagonallyacross splines.
 2. The system of claim 1, wherein the body cavity is aheart chamber and the surrounding tissue is one or more walls of theheart chamber.
 3. The system of claim 1, wherein the 3D display of thesurrounding tissue is presented on a user interface system having adisplay screen and user control mechanism enabling graphicalmanipulation of the 3D display of the surrounding tissue.
 4. The systemof claim 1, wherein the 3D array is a basket array, spiral array, aballoon, radially deployable arms, and/or other expandable andcompactible structures.
 5. The system of claim 1, wherein the 3D arrayincludes at least three splines.
 6. The system of claim 1, wherein atleast two ultrasound transducers are disposed on each spline.
 7. Thesystem of claim 1, wherein at least some of the biopotential electrodesand at least some of the ultrasound transducers are disposed on the samesplines.
 8. The system of claim 1, wherein one or more splines comprisea plurality of electrode/transducer pairs.
 9. The system of claim 1,wherein a plurality of splines comprise at least oneelectrode/transducer pair.
 10. The system of claim 1, wherein eachspline comprises a flexible PCB, and each electrode/transducer pair iselectrically coupled to the flexible PCB.
 11. The system of claim 1,wherein each electrode/transducer pair shares a common communicationpath.
 12. The system of claim 1, wherein all electrode/transducer pairson a spline share a common communication path.
 13. The system of claim1, wherein all electrode/transducer pairs on a spline share a commonground.
 14. The system of claim 1, further configured to correlatecardiac or other electrical activity to one or more images generatedusing an imaging device.
 15. The system of claim 14, wherein the imagingdevice comprise an imaging device selected from the group consisting of:a fluoroscope; an MRI; a CT Scanner; an ultrasound imaging device; andcombinations of two or more of these.
 16. The system of claim 1, whereinaccording to the activation sequence, at least two neighboringultrasound transducers from the same spline are not activated insuccessive time periods.
 17. The system of claim 1, further comprisingone or more switches configured to selectively open and/or close toelectrically connect the transducer to a signal generator.
 18. Thesystem of claim 17, wherein the one or more switches comprises anopto-coupler.
 19. The system of claim 18, wherein the opto-coupler hasan activation time in a range of about 0.01 μs to 500 μs.